It is known that the use and accuracy of flow measurement devices, in particular of an inductive type, are limited by low conductivity of the measurement medium and deposits which occur on the electrodes during operation. This results in contact resistances in the galvanic coupling to the measurement medium, which corrupts the measurement results.
DE 102 43 748 A1 discloses an alternating-current signal being fed in onto one of the electrodes of the flow measurement device, and being measured with respect to a ground electrode.
This has the disadvantage that the voltage measurement is interfered with or corrupted by the current-carrying electrodes.